1. Field of the Invention
The present invention relates to an ink composition applicable to an ink jet recording, an image forming method using the ink composition and a printed material formed from the ink composition.
2. Description of the Related Art
As an image recording method in which the image is formed on a recording medium such as paper based on an image data signal, there is an ink jet recording method.
The ink jet recording method is a recording method in which a liquid ink composition is discharged from a nozzle toward the recording medium using pressure, heat, an electric field or the like as a driving source and then recorded. The ink jet recording method described above has rapidly come into widespread use in recent years since operating costs are low, and high image quality is possible.
Among the ink compositions used in image recording by the image recording method, an active energy ray curable aqueous ink may be suitably used in printing of the image, with pre-treatment to apply a suitable printing property to the recording medium, and after-treatment such as protection and decoration of the printed image. Also, the active energy ray curable aqueous ink is excellent in safety since water is a main component, can be applied as high-density ink jet recording due to reduced viscosity and the like, and has many excellent features and possibilities.
As an aqueous ink composition, for example, an ink composition which includes an aqueous active energy ray polymerizable substance containing a cross-linking water-soluble polymer and cross-linking fine particles has been disclosed (for example, see JP2007-161887A). However, there is still room for improvement in water-resistance and solvent resistance of the formed image, there is also a demand for improvement in fixability (fixing property) of the image evaluated by the stickiness of the image after energy has been applied, and particularly, there is a strong demand for a system in which a polymerization initiator is not used at all, or in very small amounts.
Meanwhile, from the viewpoint of water-resistance improvement of the ink image, an ink jet ink composition containing fine resin particles made of a reactive polymer, a water-soluble polymerizable polymer and a pigment (for example, see JP2002-241702A) or the like, an ink jet ink composition containing a (meth)acrylate compound having a specified bulky partial structure and a polymerizable compound having a reactive group (for example, see JP2007-197544A), and an ink jet ink composition containing a coloring agent, a hydrophilic polymer and an aqueous medium which includes a reactive component (for example, see JP1995-257014A (JP-H7-257014A)) and the like have been disclosed.